Process and plant for the production of a fluid fine paste hardenable after molding

ABSTRACT

The process is implemented in a plant which comprises a homogenising apparatus (1) consisting of a first vertical container (10) having axial stirring devices (11) and peripheral stirring devices (12) with independently actuated blades (15), and grinding apparatus (3) comprised of an external static cylindrical body (21) with centripetally projecting stubs (24) and wherein is housed an internal rotary cylindrical body (25) provided with centrifugally projecting stubs (24); a continuous mixter (4) of which the internal surface (28) has crossing furrows (29) and wherein is housed a cylindrical body (34) of which the external surface (30) has second furrows which also cross each other, so that all the furrows form conduits which initiate in an extreme chamber (31) and which terminate in an extreme chamber (32) for the outflow of fluids resulting from produced mixtures; and a nozzle (5) for supplying the fine fluid paste, said nozzle being comprised of a main tubular body (33) having on the one hand an extreme annular enclosure (36) provided with second inlet nozzles (37) for additives and pressure gas fluid and, on the other hand, outlet conduits which open into ports (38) of the main tubular body (33).

The invention relates to a process for the production of a fluid finepaste hardenable after molding, and more particularly fluid pastesprepared from materials such as cement, clays, kaolin and the like inadmixture with water and other additives to form solid bodies oncehardened by setting, heating or polymerization, particularly fluidpastes composed of solid materials, such as cement, clays, kaolin andthe like in admixture with water and other compatible complementaryproducts, such as aggregates, dyestuffs, fillers, fiber reinforcements,polymers, etc., and functional additives such as inhibitors,accelerators, thixotropic agents, fluidisers, foaming agents, etc., toform solid bodies, after molding and hardening by setting, heatingand/or polymerization, applicable in the building industry. The listingof such materials in which the preferred ones of the said industry arecited, is given only as a guidance and is in no way restrictive, itbeing of application to other industries, such as the chemical, food,naval, paint manufacturing and others.

The invention also relates to a plant for the production of a fluid finepaste hardenable after molding.

The solid bodies, obtained with the materials listed as preferred, areprefabricated elements for the building industry, such as frontagepanels, internal closure partitions, tiles and floor tiles, piecesimitating natural stones (marble, granite, etc.), indoor and outdoorchimneys, urban furnishing, imitation wood pieces, swimming pools,cisterns, irrigation canals and many more.

For making such solid bodies, the present applicant filed Spanish patentapplication 9502438 relative to a process and a plant for carrying outthe process, in which the starting material was an air hardenable fluidmaterial.

The working of the subject matter of the above application has enabledthe constitution of the said fluid material to be improved, convertingit into a fluid fine paste allowing the details of the molds to bereproduced more faithfully, the process for the preparation of the saidfluid fine paste and one possible plant for the preparation thereof thesubject matter of the present invention.

On the other hand, several ways are known of preparing homogenousmixtures of materials, such as those disclosed in the following Spanishpatents 544,222 (Madera) which consists of a mixing plant for producingmortars, renderings and the like, in which a vertical mixing machinereceives the products to be mixed and homogenizes them; 2,009,650(Rosell) consisting of a mortar mixing machine for the buildingindustry, in which the mixer is horizontal and has a turbine shaft formixing the dry mortar with the water; and 2,013,158 (Fabregat),consisting of a mixing apparatus for mortars, paints and paste-likematerials, formed by an open container having a tumbling tool formed bya shaft coupled to a powered machine

It is an object of the invention to provide a process and a plant forpreparing the said fluid fine paste in a perfectly homogenized conditionand having a composition appropriate for each application, since theyallow for the combination of a large numbers of parameters, whether theybe mechanical operations or addition components.

The process is characterized in that the basic solid and liquid productsfor forming the fluid paste are mixed in a homogenizing apparatus, inwhich the said basic products are dispersed and kneaded, together withaddition components, to obtain a first fluid homogenous mixture, whichis thereafter fed to a grinding apparatus, in which the coarse particlesand lumps present in the said first fluid homogenous mixture are groundand to which there may be added coloring agents, as the case may be, togive a second homogenous fluid fine mixture which is thereaftertransferred to a continuous mixer, where additives and/or coloringmatter are added, forming a fluid fine paste which is continuously fedto a delivery nozzle for said fluid fine paste to which more additivesare added and, optionally, reinforcing fibers and/or a gaseous foamingfluid.

In turn, the plant is characterized in that it comprises a homogenizingapparatus, a grinding apparatus, a continuous mixer and a deliverynozzle for a fluid fine paste. The homogenizing apparatus is formed by afirst vertical vessel, having internal stirring means for the mixture tobe homogenized; said means comprising: [a] axial means formed by arotary vertical and axially moveable shaft which, at the lower endportion thereof, is provided with at least one generally discoidstirring element and, at the end portion thereof external to said firstvertical vessel, with a drive means; and [b] peripheral means formed byat least one blade which moves around an internal peripheral region ofthe first vertical vessel and is provided with a ploughshare-likewidening at the upper end thereof, slopingly disposed relative to theplane of rotation and in the direction of the movement thereof; saidperipheral means being driven by a rotary drive means causing it torotate in the opposite direction to the direction of rotation of saidaxial means.

The grinding apparatus is formed by a static external cylindrical body:[a] which is provided with a cover plate at one end, said plate havingfirst inlet ports; and a discharge port at the other end thereof; [b]which is provided with a plurality of cylindrical stubs which: [i]extend radially inwardly from the inner surface thereof; [ii] arearranged in groups and the different groups are disposed in equidistantparallel planes; and [iii] each stub of one of said groups is axiallyaligned with stubs of the remaining groups; [c] which comprisesinternally thereof a rotary internal cylindrical body, which: [i] has asmaller diameter that the distance between opposite stubs; [ii] has aplurality of ovalised stubs extending radially outwardly from the outersurface of said rotary internal cylindrical body and which are arrangedin equidistant parallel planes, inserted between the planes defined bysaid cylindrical stubs; and [iii] each of said ovalised stubs defines asloping plane of symmetry.

The continuous mixer: [a] defines a first internal cylindrical surface,slotted by first crossing furrows forming first crossover points andfirst squares defining a first grid square; and [b] snugly houses acylindrical body defining a second external cylindrical surface: [a]5directly and snugly engaging said first internal cylindrical surface;[ii] slotted by second also crossing furrows forming second crossoverpoints and second squares defining a second grid square; and said firstcrossover points of said first furrows of said first internalcylindrical surface are centered over said second squares of said secondexternal cylindrical surface, while said second crossover points of saidsecond furrows of said second external surface are centered on saidfirst squares of said first internal surface, so that all the furrowsform passages which start at an end inlet chamber for the fluids to bemixed and terminate in an end discharge chamber for the fluids resultingfrom the mixing caused by the passage of said fluids through saidfurrows.

To facilitate an understanding of the foregoing ideas, there isdescribed hereinafter the process and one embodiment of the plant forcarrying out the process and of constituent elements thereof, withreference to the accompanying illustrative drawings, in which:

FIG. 1 is a schematic elevation view of a plant according to theinvention, for carrying out the said process;

FIG. 2 is a schematic elevation view, partly in axial section, of thehomogenizing apparatus for the basic mix;

FIG. 3 is a schematic axial cross section view of the grinding apparatusfor the basic homogenous fluid mix from the homogenizing apparatus;

FIG. 4 is a schematic axial cross section view of the continuous mixerfor the fine homogenous fluid mixture from the grinding apparatus;

FIG. 5 is a schematic axial cross section view of the nozzle deliveringthe fluid fine paste under suitable conditions for molding.

The essential components of the instant plant, consisting of ahomogenizing apparatus 1, a collecting pan 2, a grinding apparatus 3, acontinuous mixer 4, a delivery nozzle 5 and two spray stations 6 for thereinforcement fibers 7 on the spray cone 8 of the fluid fine paste to becast in a mold 9 are shown in consecutive order in FIG. 1.

The homogenizing apparatus 1 is formed by a first vertical vessel 10having internal stirring means for the mix to be homogenized. Theinternal means are differentiated between axial means 11 and peripheralmeans 12, the former being constituted by a rotary vertical and axiallymoveable shaft which, at the lower end portion thereof, is provided withat least one generally discoid stirring member 13 and, at the endportion external to said first vertical vessel 10, with a motor device14. In turn, the peripheral means 12 is formed by one or more blades 15which, moving around the internal peripheral region of the firstvertical vessel 10, are provided with a ploughshare-like widening at theupper end thereof, slopingly disposed relative to the plane of rotationthereof, and they are driven by a rotary device causing them to rotatein the direction X contrary to the direction Y of rotation of the axialmeans 11. The lower portion of the first vertical vessel 10 is shapedlike a hopper 17 and is closed by a gate valve 18 which, driven by adrive means 19, discharges a homogenized mass or first fluid homogenousmix into the collecting pan 2, which is provided with a motor pump 20driving the mass towards the grinding apparatus 3 up to the deliverynozzle 5.

The grinding apparatus 3 is formed by a static external cylindrical body21 provided, at one end thereof, with a cover plate 22 and, at the otherend thereof, with a discharge port 23. Within the body 21 there is aplurality of cylindrical stubs 24, extending radially inwardly from theinner surface of the static external cylindrical body 21. These stubs 24are arranged in groups and the different groups are disposed inequidistant parallel planes; and furthermore each stub of one of saidgroups is axially aligned with stubs of the remaining groups. Within thebody 21 there is housed a rotary internal cylindrical body 25, having asmaller diameter that the diameter defined between opposite cylindricalstubs 24 and having a plurality of ovalised stubs 26 extending radiallyoutwardly from the outer surface thereof, said stubs being arranged inequidistant parallel planes, inserted between the planes of saidcylindrical stubs 24; and having their individual plane of symmetrysloping in a direction contrary to that of rotation of the body. Thecover plate 22 is provided with first inlet ports 27 for the firsthomogenous fluid mix, additives and coloring agents and water forpressurized cleaning. A second fluid homogenous mix exits from thegrinding apparatus 3.

The continuous mixer 4 comprises a tubular body 33 having a firstinternal cylindrical surface 28, slofted by first crossing furrows 29forming first crossover points and first squares defining a first gridsquare. Within the tubular body 33 there is snugly housed a cylindricalbody 34, which may be tubular or not. The body 34 has a second externalcylindrical surface 30 slotted (by means of second furrows formingfurther crossover points and further squares, the configuration of whichis also as a grid square) in a similar fashion to the first internalsurface 28 and directly and snugly engaging said first internal surface28. The crossover points of the furrows 29 of the first internal surface28 are located over the center of the squares of the second externalsurface 30 and vice versa, such that all the furrows, which arecontinuous, form passages which start at an end inlet chamber 31 for thefluids to be mixed and terminate in an end discharge chamber 32. Thefluid fine paste resulting from the mixing caused by the passage of thematerials through these furrows exits from the chamber 32.

The delivery nozzle 5 for the fluid fine paste is formed by a maintubular body 35 comprising an annular end enclosure 36 which isprovided, on the one hand, with second inlet nozzles 37 for additivesand a pressurized gaseous fluid and, on the other hand, with outletconduits terminating in ports 38 in the main tubular body 35 downstreamof the annular end enclosure 36.

The discharge port of the delivery nozzle 5 is provided with means 39for forming the outlet jet of the fluid fine paste. The delivery nozzle5 is associated, furthermore, with the two spraying stations 6 for thereinforcement fibers 7 for incorporating these reinforcement fibers 7 inthe spray cone 8 of the fine paste.

I claim:
 1. A plant for preparing a fluid fine paste hardenable aftermolding, comprising a homogenizing apparatus (1); a grinding apparatus(3); a continuous mixer (4) which defines a first internal surface; anda delivery nozzle (5) for a fluid fine paste, characterized in that:saidfirst internal surface of said continuous mixer is slotted by firstcrossing furrows (29) forming first crossover points and first squaresdefining a first grid square; said continuous mixer (4) snugly houses acylindrical body (34) defining a second external cylindrical surface(30): [i] directly and snugly engaging said first internal cylindricalsurface (28); [ii] slotted by a second also crossing furrows formingsecond crossover points and second squares defining a second gridsquare; and in that said first crossover points of said first furrows(29) of said first internal cylindrical surface (28) are centered oversaid second squares of said external cylindrical surface (30), whilesaid second crossover points of said second furrows (29) of said secondexternal surface (30) are centered on said first squares of said firstinternal surface (28), so that the furrows form passages which start inan end inlet chamber (31) for the fluids to be mixed and terminate in anend discharge chamber (32) for the fluids resulting from the mixingcaused by the passage of said fluids through said furrows.
 2. The plantof claim 1, characterized in that said homogenizing apparatus (1) isformed by a first vertical vessel (10), having internal stirring meansfor the mixture to be homogenized; said means comprising: [a] axialmeans (11) formed by a rotary vertical and axially moveable shaft which,at the lower end portion thereof, is provided with at least onegenerally discoid stirring element (13) and, at the end portion thereofexternal to said first vertical vessel (10), with a motor device (14);and [b] peripheral means (12) formed by at least one blade (15) whichmoves around an internal peripheral region of the first vertical vessel(10) and is provided with a ploughshare-like widening at the upper endthereof, slopingly disposed relative to the plane of rotation thereofand in the direction of the movement thereof; said peripheral means (12)being driven by a rotary means (16) causing it to rotate in the oppositedirection to the direction of rotation of said axial means (11).
 3. Theplant of claim 1, characterized in that said grinding apparatus (3) isformed by a static external cylindrical body (21):[a] which is providedwith a cover plate (22) at one end, said plate having first inlet ports(27); and a discharge port (23) at the other end thereof; [b] which isprovided with a plurality of cylindrical stubs (24) which: [ii] extendradially inwardly from the inner surface thereof; [i] are arranged ingroups and the different groups are disposed in equidistant parallelplanes; and [iii] each stub (24) of one of said groups is axiallyaligned with stubs (24) of the remaining groups; [c] which comprisesinternally thereof a rotary internal cylindrical body (25), which: [i]has a smaller diameter that the distance between opposite stubs (24);[ii] has a plurality of ovalised stubs (26) extending radially outwardlyfrom the outer surface of said rotary internal cylindrical body (25) andwhich are arranged in equidistant parallel planes, inserted between theplanes defined by said cylindrical stubs (24); and [iii] each of saidovalised stubs (26) defines a sloping plane of symmetry.
 4. The plant ofclaim 1, characterized in that said delivery nozzle (5) for the fluidfine paste is formed by a main tubular body (35) comprising an annularend enclosure (36) which is provided, on the one hand, with second inletnozzles (37) for additives and a pressurized gaseous fluid and, on theother hand, with outlet conduits terminating in ports (38) in the maintubular body (35) downstream of the annular end enclosure (36).
 5. Theplant of claim 4, characterized in that said delivery nozzle (5) isprovided with a discharge port having means (39) for forming the outletjet of the fluid fine paste.
 6. The plant of claim 4, characterized inthat said delivery nozzle (5) is associated with means for incorporatingreinforcement fibers in the fine paste.